Porter Manufacturing Company uses the perpetual inventory system to account for its manufacturing inventories. The following are Porter's transactions during September. For T-accounts, enter transactions in order of occurrence using the first available answer box in the appropriate debit or credit column. \begin{tabular}{|l|r|r|} \hline & \multicolumn{2}{|c|}{ Materials Inventory } \\ \hline Bal. & 4,000 & 4,000 \\ \hline & 1,500 & 0 \\ \hline Bal. & 4,000 & 0 \\ \hline \end{tabular} \begin{tabular}{|r|r|r|} \hline & \multicolumn{2}{|c|}{ Finished Goods Inventory } \\ \hline Bal. & 5,500 & 0 \\ \hline & 0 & 0 \\ \hline Bal. & 0 & 0 \\ \hline \end{tabular} \begin{tabular}{|c|c|c|} \hline \multicolumn{3}{|c|}{ Work in Process Inventory } \\ \hline Bal. & 13,000 & 0x \\ \hline & 0 & 0 \\ \hline & 0 & 0 \\ \hline & 0 & 0 \\ \hline \end{tabular} \begin{tabular}{|r|r|r|} \hline & \multicolumn{2}{|c|}{ Cost of Goods Sold } \\ \hline Bal. & 16,000 & 0 \\ & 0 & 0 \\ \hline Bal. & 0 & 0 \\ \hline \end{tabular}